1. Field of the Invention
This invention concerns a strip of single dose or multiple dose containers for liquids, pastes or powders, for pharmaceutical, diagnostic, cosmetic or similar uses, made of plastic material by injection moulding and joined between themselves by removable couplings.
2. Discussion of the Background
Container strips of this type are well known and must be extensively adjusted before being placed on the market.
In particular, the containers of the strip are substantially tubular in shape, with one open end for the filling of the product. The moulded strips are placed in a hopper and transferred from there onto machines which supply the various functional groups which control, for example, the operations of transfer, filling, closing and welding of the containers, as well as packaging or alignment or boxing of bare strips or strips contained in packages and so on.
The individual containers of each strip are normally joined together by two series of fins or bridges: a series of fins set in an intermediate position along the containers and a series of fins set at level of the capped ends of the containers, provided with a plug obtained during moulding. The two series of fins are disposed in the plane containing the axes of the containers and are provided with weakening creases or pre-fracture lines which allow the separation of the individual containers during use. The containers are opened at the far end by twisting the plug.
The biggest problem which occurs with these strips of containers is that due to a lack of rigidity, they tend to get entangled, to overlap, to become deformed or to break, either during filling, positioning into the machine, or during the various manufacturing steps. To try to overcome these difficulties, EP-B-0 326 529 proposes a container strip in which:
the intermediate and terminal junction fins which join the bodies of the individual containers have arrow shaped pre-fracture lines, or are at least, diverging with respect to the axes of the containers; PA1 the ends of the series of intermediate and terminal fins have transverse butts disposed at right angle to the plane occupied by the fins, aligned between themselves and having a width less, or at the most, equal to the thickness of the containers; the intermediate, transverse butts are connected on both sides to the respective end fins by one or more triangular ribs; the terminal fins are deeper to have a greater width and are provided with external ribs as wide as the transverse butts, tapered towards the area of the weakening creases; PA1 the free terminal section of the body of each container has an external cylindrical thickening.
This solution has been adopted particularly to reduce the possibility of entangling and overlapping of the strips.
However, the solution proposed in EP-326 529 does not completely solve these problems, as the strips of containers leaving the injection press while they are still hot, tend to bend and are consequently still subject to overlapping and entanglement during the successive operations.